A quarter fender is typically affixed to each outer side of the frame rails of a vehicle (especially a semi-tractor) in front of a set of non-steered wheels (including single wheels, double wheels, and wheels in tandem), such that the tires are protected from foreign objects, the cab is protected from impact by any forward-propelled splash/spray/debris from the rotating wheels, and some protection from tire damage is provided to surrounding equipment in the event of a blowout. In addition, quarter fenders may provide some aesthetic purpose.
The shape and orientation of a quarter fender is generally based on preventing rocks from striking the cab, contact (or no contact) with a trailer, and ensuring a driver or mechanic can access parts on the tractor chassis. They typically have a general curvature with respect to a proximal wheel.
FIG. 1 depicts a perspective view of a standard quarter fender 100 having mounting pipe 102 and clamp 110 coupled to deflector flap 108 using fasteners 106. Existing quarter fenders 100 typically mount forward of the tractor's non-steered wheel assemblies 116, and are pivotal about the mounting pipe 102 such that the user can adjust quarter fender 100 to best seal a gap between the truck and the trailer or to obtain a desired appearance, for example. A quarter fender deflector flap typically mounts to the top of the quarter fender using nuts and bolts, for example, and is a substantially flat, flexible piece of plastic or rubber, sometimes with a particular 2-dimensional cutout pattern, graphic, or texture.
FIGS. 2 and 3 depict partial perspective and partial side views of a tractor 60 coupled to a trailer 120 constituting a tractor-trailer combination vehicle. FIGS. 2 and 3 further illustrate standard quarter fender 100 installed on tractor 60, whereby quarter fender 100 comprises mounting pipe 102 connected to quarter fender panel 100 with mounting hardware 106. Quarter fender 100 typically receives a deflector flap 108, which may be secured with mounting hardware 106. Quarter fender 100 is typically mounted to the tractor with mounting pipe 102 connecting to mounting stud (not shown) and secured with clamp 110 to the stud, which is typically permanently affixed to frame rail 112 or sometimes to suspension bracket 114, or other bracket. FIG. 3 further depicts a gap 122 commonly found between trailer 120 and flap 108.
FIG. 4 depicts a perspective view of quarter fender 100 installed on a vehicle. As shown in FIG. 4, there are usually components, for example steps 22, cylinder 80, that should be readily accessible for servicing, inspecting etc. Thus, quarter fenders 100 typically do not extend into this space. In some cases, a fuel tank fairing or other body component of the vehicle may extend into this space, thereby reducing or eliminating this space.
One problem with quarter fenders is the inability to properly align the quarter fender with the tire, trailer, etc. to achieve a desired air flow, minimize spray/splash or debris, or prevent rocks and debris from being propelled back toward the cab. As a result of the inability to accurately and consistently position or orient a quarter fender, the air flow may be asymmetric, may increase spray, splash, or aerodynamic drag, may not protect against blowouts, and other undesirable outcomes.
Additional problems exist for quarter fenders that have deflector flaps designed to contact the trailer such that no gap exists between the trailer and the top of the quarter fender. For example, deflector flaps are frequently impacted by the bottom of a trailer when the trailer is being loaded or unloaded from the tractor. Depending on the position of the flap, the trailer may contact and affect the flap. As a result, the thickness and material of many existing flaps are designed to deflect easily out of the way under a vertical load. But many times they are subjected to awkward loading by the trailer and may buckle, fail catastrophically, deform inelastically, or otherwise fail over time. These deflector flaps are manufactured with a planar surface and angled either forward or backward to reduce damage from contact with the trailer.